Muffling apparatus having exhaust emission purifying function

Abstract

A muffling apparatus 1 of the present invention having an exhaust emission purifying function, including a turning portion 8 in an inside of an exhaust gas flow passage, and having an injection nozzle 12 disposed in an upstream side exhaust gas flow passage 9 of the turning portion 8 , for injection-supplying a liquid reducing agent; and a reduction catalytic converter 13 disposed in a downstream side exhaust gas flow passage 10 of the turning portion 8 , for reductively purifying nitrogen oxides with the liquid reducing agent. The apparatus further includes a diffusing member 15 , which generates a vortex flow of a gas traveling in a vertical plane of the turning portion 8 to diffuse the liquid reducing agent.

1. A muffling apparatus having an exhaust emission purifying function, the apparatus being formed with a turning portion in an inside of a flow passage of an exhaust gas, and comprising at least:
 an injection nozzle, disposed in the flow passage of the exhaust gas on an upstream side of the turning portion, for injection-supplying a liquid reducing agent; and 
 a reduction catalytic converter, disposed in the flow passage of the exhaust gas on a downstream side of the turning portion, for reductively purifying nitrogen oxides with the liquid reducing agent, and 
 a diffusing member for generating a vortex flow of gas traveling in a vertical plane of the turning portion to cause diffusion of the liquid reducing agent into the exhaust gas flow, the diffusing member including a ring member on which a plurality of opening portions are formed, the opening portions arranged on a side of the ring member and disposed substantially in parallel with a flow direction of the exhaust gas entering into the turning portion from the flow passage of the exhaust gas on the upstream side of the turning portion, 
 wherein the exhaust gas entering into the turning portion is injected in outward directions via the opening portions to thereby generate the vortex flow. 
 
   
   
     2. The muffling apparatus having an exhaust emission purifying function according to  claim 1 , wherein the ring member leads the exhaust gas which flows into the turning portion from the upstream side exhaust gas flow passage, toward a direction in which a turning portion wall face extends substantially in parallel with a flow direction of the exhaust gas. 
   
   
     3. The muffling apparatus having an exhaust emission purifying function according to  claim 1 , wherein the plurality of opening portions are formed to be arranged at a non-uniform distribution in the circumferential direction of the ring member. 
   
   
     4. The muffling apparatus having an exhaust emission purifying function according to  claim 1 , wherein the plurality of opening portions are formed to have different hole-diameters from each other. 
   
   
     5. The muffling apparatus having an exhaust emission purifying function according to  claim 1 , wherein an oxidation catalytic converter is provided on an upstream side of the injection nozzle, for oxidizing nitrogen monoxide into nitrogen dioxide, and a reducing agent oxidation catalytic converter is provided on a downstream side of the reduction catalytic converter, for oxidation-purifying the liquid reducing agent which has passed through the reduction catalytic converter.